JPH065868B2 - Document reader - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Outline] The present invention relates to a document reading apparatus capable of automatically identifying a paper type of a document and detecting a double feed of two or more documents, and identifying a paper type of a document in the document reading apparatus. For the purpose of improving the operability by enabling automation such as double feed detection and double feed detection, the photoelectric conversion element and the opposite side of the photoelectric conversion element sandwiching the original are placed to illuminate the back side of the original. At least one of the illumination lamps also serves as that of a normal reading unit, and the amount of light from the illumination lamps that passes through the document is detected by the photoelectric conversion element to identify the paper type of the document or two sheets. The above-described document double feed detection is configured.

[Industrial application field]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a document reading device capable of automatically identifying the paper type of a document and detecting so-called double feed of two or more documents.

In order to improve the operability and reduce the cost of the document reading device, it is strongly desired to automate the sheet type identification of the document and to simplify the structure of the document double feed detecting means.

[Conventional technology]

Generally, a reading unit (hereinafter referred to as a CCD unit) having an illumination lamp for illuminating the surface of the original and a photoelectric conversion element (hereinafter referred to as CCD) for reading an image on the surface of the original is provided, and the CCD unit and the original are provided. There is known a document reading apparatus configured to read images such as characters on the document surface by relatively moving and. Then, the sheet type of the original includes a sheet having a low light transmittance and a film having a high light transmittance (for example, a film original (hereinafter referred to as a transparent original)). Further, among the above-mentioned papers having a low light transmittance, there are a paper that transmits almost no light (hereinafter referred to as a reflection original) and a paper that transmits light to some extent (hereinafter referred to as a thin paper original). An original reading device with a transparent unit is known which can read any of the transparent original, the reflective original, and the thin original.

The original reading device with a transmissive unit includes a transmissive unit having a transmissive lamp, which is provided on the opposite side of the CCD unit with the original sandwiched between the illumination lamp for reading the original and illuminates the original from the back side. Document reading device. Then, when the paper type of the original is a transparent original, the illumination lamp is not turned on and only the transparent lamp is turned on to read the original, and in the case of a reflective original, the transparent lamp is not turned on. The original is read by turning on only the illumination lamp, and in the case of a thin paper original, for example, the original is read while both the transmissive lamp and the illumination lamp are turned on. That is, it is necessary to control the lighting of the illumination lamp and the transmissive lamp in accordance with the paper type of the original. And in the past,
Regarding the lighting control of the illumination lamp and the transmission lamp, the operator manually determines the paper type of the original document and artificially operates in a control mode corresponding to each paper type.

Further, in a document reading device equipped with an automatic document feeding device, it is necessary to prevent occurrence of document reading error due to double feeding of the document. Therefore, a document double feed detecting means is provided to detect the occurrence of double feed of the document.

As shown in FIG. 9, the conventional double-feed detecting means has a light-emitting element 10 and a light-receiving element 6 for double-feed detection so as to face each other with the original 5 interposed therebetween, and detects the light transmittance of the original. By doing so, it is possible to detect the occurrence of the double feed state of the document fed from the automatic paper feeding device (not shown). Incidentally, reference numeral 4 in FIG.
Is a CCD unit including a reflecting mirror 4-2 and a lens 4-
3, reference numeral 4-1 indicates an illumination lamp, and reference numeral 7 indicates an original feeding roller.

[Problems to be Solved by the Invention]

As described above, in a conventional document reading apparatus with a transmissive unit capable of reading a document regardless of the type of the document, that is, a transparent document, a reflective document, or a thin document, the operator can It is necessary to perform the complicated operation of determining the sheet type of No. 1 and artificially selecting the reading control mode corresponding to each sheet type.

Further, in the conventional double feed detecting means shown in FIG. 9, a light emitting element and a light receiving element dedicated for double feed detection are required, so that not only the configuration becomes complicated but also the cost increases. There was an undesired problem.

Further, in order to automatically check the paper type of the original, a specially prepared photoelectric conversion element is required.

The present invention is intended to solve the above-mentioned undesired problems, and an object of the present invention is to improve operability by enabling automation such as identification of a sheet type of a document and double feed detection. .

[Means for Solving the Problems]

FIG. 1 is a principle block diagram of a document reading apparatus according to the present invention. Reference numeral 1 in the figure is a CCD unit, 1-1
Is an illumination lamp, 1-2 is a reflecting mirror, 1-3 is a lens, 1-
4 is a CCD, 2 is a transmissive unit, 2-1 is a transmissive lamp,
Reference numeral 2-2 represents a transparent plate, and 3 represents a document placing plate.

The principle block diagram of FIG. 1 shows a document reading apparatus for improving the operability by automatically executing the identification of the sheet type of the original and the selection control of the reading mode corresponding to the sheet type. A schematic diagram is shown.

In FIG. 1, the above-mentioned C
This is performed by the CD unit 1 and the transmissive lamp 2-1, but in identifying the sheet type of the original document prior to that, the illumination lamp 1-1 in the CCD unit 1 is not turned on and the transmissive lamp 2-1 in the transmissive unit 2 is turned on. It is performed under the condition that it is lit. That is, the CCD 1-4 detects the amount of light transmitted through a document (not shown) placed on a transparent document placing plate 3 such as a glass plate,
Since the amount of light transmitted through the original differs depending on the paper type of the original (transparent original, reflective original, thin paper original), the CC
Identification of the paper type of the original based on the output signal level of D1-4 (identification of transparent original, reflective original or thin original)
Is done.

Next, based on the result of identifying the paper type of the original,
The reading mode selection control is performed and the document reading is executed. That is, in the case of a reflection original, the transmission lamp 2-1 is not turned on, but the illumination lamp 1-1 is used.
Only light up.

In the case of a transparent original, the illumination lamp 1-1 is not turned on, but the transparent lamp 2-1 is used.
Only light up.

In the case of a thin paper document, both the illumination lamp 1-1 and the transmission lamp 2-1 are turned on.

FIG. 2 is another principle configuration diagram of the document reading apparatus according to the present invention. Reference numeral 4 in the figure is a CCD unit, 4-
1 is an illumination lamp, 4-2 is a reflecting mirror, 4-3 is a lens, 4
-4 is a CCD, 5 is a document, 6 is a light receiving element, and 7 is a document feeding roller.

The principle block diagram of FIG. 2 shows a schematic diagram of a document reading apparatus having a document double feed detecting means according to the present invention.

In FIG. 2, the CCD unit 4 including the reflecting mirror 4-2, the lens 4-3, and the CCD 4-4 and the illumination lamp 4-1 are known document reading means. In the embodiment shown in FIG. 2, the light transmittance of the document is detected by the light receiving element 6 by using the illumination lamp 4-1 in the document reading means. Since the light transmissivity detected by the light receiving element 6 is different between the case where one original is fed and the case where two or more originals are overlapped, the double feed detection of the original cannot be performed. Done.

[Action]

As described above, according to the principle configuration of the present invention shown in FIG. 1, by automatically executing the identification of the paper type of the document and the selection control of the reading mode corresponding to the paper type, The operability can be improved.

Further, according to the document structure of the present invention shown in FIG. 2, since the illumination lamp 4-1 in the document reading unit is used as the light source in the document double feed detecting unit, the double feed detecting unit The simplification can be achieved and the cost can be reduced.

〔Example〕

FIG. 3 is a CCD output waveform diagram in the embodiment shown in FIG.
FIG. 4 is an operation flow chart showing the operation in the embodiment shown in FIG. 1, FIG. 5 is an operation flow chart showing the double feed detection operation in the embodiment shown in FIG. 2, and FIGS. Another embodiment of the document reading apparatus according to the present invention will be described.

With reference to FIG. 3 and FIG. 4, the operation of the identification of the sheet type of the original and the control of the selection of the reading mode corresponding to the sheet type in the embodiment shown in FIG. 1 of the present invention will be specifically described. . It should be noted that FIG. 3A shows a CCD output waveform when the original paper type is a thin paper original, and FIG. 3B shows a CCD output waveform when the original paper type is a transparent original.

In the embodiment shown in FIG. 1, the operation of identifying the paper type of the original is started by executing step (1) shown in FIG.

In step (1), with the illumination lamp 1-1 in the CCD unit 1 turned off, the transmission unit 2
The transmissive lamp 2-1 is turned on.

Next, in step (2), it is determined whether or not there is an output from the CCD 1-4. In the case of a reflective original, the irradiation light from the transmissive lamp 2-1 hardly passes through the reflective original, so when the CCD 1-4 does not output, it means that the paper type of the original is a reflective original. . In addition,
If the paper type of the original is a thin paper original, the CCD1-
The output of No. 4 has a waveform as shown in FIG. 3 (A), and when the original paper type is a transparent original, the above C
The output of CD1-4 has a waveform as shown in FIG. 3 (B). Therefore, when the CCD 1-4 outputs, it means that the paper type of the original is a thin original or a transparent original. Then, it is determined in step (4) described later whether the paper type of the original is a thin original or a transparent original.

If the determination in step (2) above indicates that there is no output (that is, if the document sheet type is a reflective document), the process proceeds to step (3). In step (3), the original reading operation is started with the transmissive lamp 2-1 turned off and the illumination lamp 1-1 turned on so that the original reading operation on the reflective original can be efficiently performed. (Step (7)).

If there is an output in the step (2), the process proceeds to step (4) and it is determined whether the sheet type of the original is a thin original or a transparent original. The determination is made based on the output waveform of the CCD 1-4 (shown in FIG. 3). That is, the difference value d between the black level value a and the white level value b in the output waveform of the CCD 1-4 (shown in FIG. 3A) when the original paper type is a thin original is the original paper type. CC when the original is transparent
It is smaller than the difference value D between the black level value a and the white level value b ′ in the output waveform of D1-4 (shown in FIG. 3B). Therefore, the difference value between the white level value and the black level value in the output waveform of the CCD 1-4 is set to a predetermined threshold value M.
(For example, M = (d + D) × 1/2)
<M> means a thin paper document, and “D> M” means a transparent document.

When the determination in step (4) is “d <M” (that is, when the document type of the document is a thin document), the process proceeds to steps (5) and (6). In order to efficiently perform the document reading operation on the thin paper document, both the illumination lamp 1-1 and the transmission lamp 2-1 are turned on in step (5), and the white level value b ( The original reading operation is started after the dimming of the transmissive lamp 2-1 is performed so that the level shown in FIG. 3B becomes a predetermined level value (for example, the white level value b ′). (Step (7)).

Further, the determination in the above step (4) is “D>
In case of "M" (that is, when the original paper type is a transparent original)
In order to efficiently perform the original reading operation on the transparent original, the illumination lamp 1-1 and the transparent lamp 2-1 remain set in the step (1) (that is, the transparent lamp 2-1). → Lighting, lighting lamp 1-1
→ The light is turned off), and the document reading operation is started (step (7)).

As described above, according to the embodiment shown in FIG. 1, the operability is improved by automating the identification of the paper type of the original document, and the contrast is always stable regardless of the paper type of the original document. It is possible to obtain highly reliable image data.

Next, the operation of the document double feed detecting means in the embodiment shown in FIG. 2 of the present invention will be specifically described with reference to the operation flow shown in FIG.

In the embodiment shown in FIG. 2, the illumination lamp 4-1 for reading an original is used as a light source, the light transmittance of the original is detected by the light receiving element 6, and the light transmittance (hereinafter referred to as a detected transmittance α). ) Is compared with the light transmittance of one fed original to detect double feed of the original. Therefore, the information on the light transmittance of the fed original (for example, the light transmittance (for one original) determined according to the type of paper, the thickness, etc., hereinafter referred to as the reference transmittance β) By executing the step (a) shown in FIG. 5 for setting, the detection operation regarding the double feed of the document is started.

In step (a), the reference transmittance β of the document to be fed is set.

In step (b), the illumination lamp 4-1 is turned on.

In step (c), feeding of the document 5 is started.

In step (d), the detected transmittance α is measured by the illumination lamp 4-1.

In step (e), the detected transmittance α and the reference transmittance β are compared, and if “α <β”, the document feeding state is normal. Therefore, the process proceeds to the next step (f) and the document reading is performed.

When the determination result in step (e) is “α> β”, it means that the document double feed has occurred.
Therefore, the process moves to step (g) and the error occurrence is displayed.

As described above, the embodiment shown in FIG. 2 has a configuration in which the illumination lamp in the document reading means is used as the light source in the double feed detecting means, so the double feed detecting means can be simplified. Also, in other embodiments of the present invention described later with reference to FIGS. 6 to 8, basically, similar to the embodiment shown in FIG. 2, the document reading means is used as the light source in the double feed detecting means. By using the illumination lamp in, the double feed detecting means is simplified.

In the embodiment shown in FIG. 6, the document feeding direction (the arrow direction in the figure)
A plurality of light-receiving elements 6 are arranged in a direction perpendicular to, and other configurations except this point are the same as the embodiment shown in FIG. FIG. 6 is a plan view for explaining the arrangement of the light receiving element 6, and the components other than the light receiving element 6 and the document feeding roller 7 (the CCD unit 4 shown in FIG. 2, the illumination lamp 4-). 1st grade)
Is omitted.

In FIG. 6, each of the plurality of light receiving elements 6 is associated in advance with a ground color area in a document such as a form. Then, in the embodiment shown in FIG. 6, after selecting the light receiving element 6 corresponding to the specifications (ground color area) of the form,
Double feed detection operation similar to the operation flow shown in FIG. 5 is performed. Therefore, the embodiment shown in FIG. 6 can detect the double feed at a desired position, and can perform the double feed detection without being restricted by the specification type of the document such as a form.

Then, in both the embodiments shown in FIGS. 7 and 8, the double feed detection is performed by using the illumination lamp in the document reading means as the light source in the double feed detection means, as in the embodiment shown in FIG. This is a double-sided document reading device in which the means is simplified. Reference numerals 8 and 9 in the figure denote CCD units, 8-1 and 9-.
1 is an illumination lamp, 8-3 and 9-3 are lenses, 8-4
And 9-4 represent CCDs, and other symbols correspond to those in FIG. Further, R ₁ indicates a front side reading position, and R ₂ indicates a back side reading position.

In the embodiment shown in FIG. 7, the light receiving element 6 is installed at a position facing the illumination lamp 8-1 with the original interposed therebetween. That is, the document reading device is configured to perform double feed detection by using the illumination lamp 8-1 in the CCD unit 8 as the light source in the double feed detection means.
In FIG. 7, the light receiving element 6 is arranged so as to face the illumination lamp 8-1 of the CCD unit 8, but C
The light receiving element 6 may be installed so as to face the illumination lamp 9-1 of the CD unit 9.

In the embodiment shown in FIG. 8, the illumination lamp of one of the CCD units (the illumination lamp 8-1 of the CCD unit 8 in FIG. 8) is used as the light source, and the C of the other CCD unit is used.
CD (in FIG. 8, CCD 9 of CCD unit 9
-4), the light transmittance of the document is detected to perform double feed detection.

The embodiment shown in FIGS. 7 and 8 described above is basically the same as the operation flow shown in FIG.
Performs double feed detection. In the embodiment shown in FIG. 8, if the determination result in step (e) shown in FIG. 5 is “α <β”, that is, if the document feeding is normal, the CCD unit 8 for reading the back surface is placed on the back surface. Reading position R
After moving to ₂ , scan the original.

〔The invention's effect〕

As described above, according to the present invention, the operability can be improved by automating the identification of the paper type (reflection original, thin paper original, transparent original) of the original. Also,
Since it is possible to simplify the means for detecting the double feed of the document, it is possible to greatly contribute to the cost reduction.

[Brief description of drawings]

FIG. 1 and FIG. 2 are respectively the manuscript configuration diagram of the present invention, FIG. 3 is a CCD output waveform diagram in the embodiment shown in FIG. 1, and FIG. 4 is an operation flow chart showing the operation in the embodiment shown in FIG. FIG. 5 is an operation flow chart showing the double feed detection operation in the embodiment shown in FIG. 2, and FIGS. 6 to 8 are other embodiments of the document reading apparatus according to the present invention, and FIG.
FIG. 6 is a diagram illustrating a conventional example of double feed detection means. In the figure, 1, 4, 8 and 9 are CCD units, 1-1,
4-1, 8-1 and 9-1 are illumination lamps, 1-2 is a reflecting mirror, 1-3, 4-3, 8-3 and 9-3 are lenses,
1-4, 4-4, 8-4 and 9-4 are CCDs, 2 is a transmissive unit, 2-1 is a transmissive lamp, 2-2 is a transmissive plate, 3
Reference numeral 5 denotes a document placing plate, 5 denotes a document, 6 denotes a light receiving element, and 7 denotes a document feeding roller.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A-59-137941 (JP, A) JP-A-58-152740 (JP, A) JP-A-55-37675 (JP, A)

Claims (3)

[Claims] 1. A first illumination lamp for irradiating one surface of a document and a photoelectric conversion element for reading an image on the surface of the document, and the photoelectric conversion element and the document are relatively moved. Thus, in the document reading device configured to read the document, a second illumination lamp is provided on the opposite side of the photoelectric conversion element with the document sandwiched therebetween to illuminate the other surface of the document, and the second illumination lamp that transmits the document is transmitted. The photoelectric conversion element detects the amount of light from the second illumination lamp, and means for identifying the sheet type of the document based on the white level value of the detection signal of the photoelectric conversion element. Document reader. 2. An original lamp is provided which comprises an illumination lamp for illuminating an original surface and a photoelectric conversion element for reading an image on the original surface, and the photoelectric conversion element and the original are relatively moved to read the original. In the document reading device configured as described above, a document receiving device is provided on the opposite side of the photoelectric conversion device with the document sandwiched therebetween to receive the light transmitted through the document by the illumination lamp, and two or more sheets are output based on the output of the light receiving device. The document reading device, which is configured to detect a double feed of the document. 3. A pair of reading units having an illumination lamp for irradiating both sides of the original and irradiating both sides of the original and a photoelectric conversion element are provided, and information on both sides of the original is read by the two sets of reading units. In an original reading device configured to read, the original transmitted light from the illumination lamp of either one of the two reading units is received by the photoelectric conversion element of the other reading unit, and based on the received light value. An original reading device comprising means for detecting double feed of two or more originals.